Interpreting load data
Posted: Thu Feb 06, 2025 2:52 am
Interpreting Load Data: Complete Guide
(Full Text Version - Safe for Copy/Paste)
==================================================
FOUNDATIONAL CONCEPTS
SAAMI Specifications define maximum cartridge dimensions and pressures. Critical measurements:
• OAL (Overall Length): Case base to bullet tip
• Ogive Measurement: Bullet contact with rifling
• Charge Weights: Powder ranges for tested setups
==================================================
CROSS-REFERENCING SOURCES
.308 Win 175gr Load Comparison
+—————+—————+—————+—————+
| Source | Powder | Min (gr) | Max (gr) |
+—————+—————+—————+—————+
| Hodgdon | Varget | 42.0 | 46.0 |
| Sierra | Varget | 43.5 | 47.5 |
| Lyman | Varget | 41.0 | 45.0 |
+—————+—————+—————+—————+
Velocity Ranges:
• Hodgdon: 2600-2750 fps
• Sierra: 2650-2800 fps
• Lyman: 2550-2700 fps
==================================================
COMPONENT ADJUSTMENTS
Adjustment Table
Component Adjustment Example
Lead Bullets -10% to -15% 43.5gr –> 37.0gr
Magnum Primers +5% pressure 45gr max –> 42.8gr
Military Brass -1gr to -2gr 46gr –> 44gr
==================================================
LOAD DEVELOPMENT PROCESS
1. Start 10% below max charge
2. Increment by:
• Rifle: +0.5gr per test group
• Pistol: +0.2gr per test group
3. Pressure Signs Checklist:
• Case head expansion > 0.0005”
• Primer cratering
• Stiff bolt lift
==================================================
DOCUMENTATION TEMPLATE
Logging Table
Date Bullet Powder Charge Velocity Notes
02/05/25 Hornady 75gr H4895 23.4gr 2715 fps No pressure
02/05/25 Hornady 75gr H4895 23.7gr 2742 fps Ejector mark
==================================================
CRITICAL SAFETY CHECKS
3. _ Weekly scale calibration
2. _ OAL verification every 20 rounds
3. _ Batch velocity variance <5%
4. _ Manual cross-check before loading
Copy/Paste Instructions:
1. Triple-click any section to select entire text block
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(Full Text Version - Safe for Copy/Paste)
==================================================
FOUNDATIONAL CONCEPTS
SAAMI Specifications define maximum cartridge dimensions and pressures. Critical measurements:
• OAL (Overall Length): Case base to bullet tip
• Ogive Measurement: Bullet contact with rifling
• Charge Weights: Powder ranges for tested setups
==================================================
CROSS-REFERENCING SOURCES
.308 Win 175gr Load Comparison
+—————+—————+—————+—————+
| Source | Powder | Min (gr) | Max (gr) |
+—————+—————+—————+—————+
| Hodgdon | Varget | 42.0 | 46.0 |
| Sierra | Varget | 43.5 | 47.5 |
| Lyman | Varget | 41.0 | 45.0 |
+—————+—————+—————+—————+
Velocity Ranges:
• Hodgdon: 2600-2750 fps
• Sierra: 2650-2800 fps
• Lyman: 2550-2700 fps
==================================================
COMPONENT ADJUSTMENTS
Adjustment Table
Component Adjustment Example
Lead Bullets -10% to -15% 43.5gr –> 37.0gr
Magnum Primers +5% pressure 45gr max –> 42.8gr
Military Brass -1gr to -2gr 46gr –> 44gr
==================================================
LOAD DEVELOPMENT PROCESS
1. Start 10% below max charge
2. Increment by:
• Rifle: +0.5gr per test group
• Pistol: +0.2gr per test group
3. Pressure Signs Checklist:
• Case head expansion > 0.0005”
• Primer cratering
• Stiff bolt lift
==================================================
DOCUMENTATION TEMPLATE
Logging Table
Date Bullet Powder Charge Velocity Notes
02/05/25 Hornady 75gr H4895 23.4gr 2715 fps No pressure
02/05/25 Hornady 75gr H4895 23.7gr 2742 fps Ejector mark
==================================================
CRITICAL SAFETY CHECKS
3. _ Weekly scale calibration
2. _ OAL verification every 20 rounds
3. _ Batch velocity variance <5%
4. _ Manual cross-check before loading
Copy/Paste Instructions:
1. Triple-click any section to select entire text block
2. Use “Paste as Plain Text” in your destination program
3. For perfect alignment:
• Use Courier New font
• Set tab spacing to 0.5”